High-voltage isolators are known, for example, from EP 1 933 347 A1. A tubular high-voltage isolator can have an epoxy isolating tube, which is adhesively bonded at both of its ends into annular metal holders. The end of the metal holder facing the isolating body is toroidal and is used to homogenize the electrical fields which act during operation. The torus itself may have slots which run in the axial and at the same time in the radial direction of the torus, this subdividing the torus into segments arranged in the form of a ring, in order to reduce stiffness of the torus. Apertures or slots provided in this way on the torus can affect the operation of the torus as a field control element and can allow lateral forces which occur to be passed to the isolating tube, which is rigidly adhesively bonded to the holder, and this can lead to damage to the isolator.
EP 1 657 731 A1 discloses a high-voltage switch which is in the form of a generator switch and has a cooling element, in which the cooling element extends between the current-carrying inner conductor and the encapsulation of the switch. An isolating tube composed of glass is provided between the evaporator and condenser, for electrical isolation between the cooling element evaporator on the high-voltage switch housing and the cooling element condenser on the inner conductor, which is at high voltage. Tubular connection pieces on both sides of the isolating tube connect the isolating tube to the evaporator and condenser. Together with the evaporator and the condenser, the isolating tube forms a cooling element.
U.S. Pat. No. 6,521,839 discloses a switching device in whose interior a switching rod is guided. The switching rod has a cylindrical isolating tube, in each of whose two ends a solid connecting rod is guided. The isolating tube and the connecting rod are secured with respect to one another by a countersunk bolt, thus preventing axial play between the isolating tube and the connecting rod. The junction area between the isolating tube and the connecting rod is surrounded by a metal ring, which is provided with a groove, in order to relax the electrical fields.
JP 01154419 discloses a switching device which has a switching rod. The switching rod has an isolating tube which is held by an adapter piece in the form of a cup. The adapter piece contributes to the reduction of electrical fields that occur.